A new synthetic drug that can be purchased online and is connected to at least 50 deaths nationwide has several states scrambling to stop its spread, with Kansas law enforcement agencies seeking an emergency ban.

At least three other states — Ohio, Wyoming and Georgia — already have taken action to ban U-47700 after it was connected to overdoses. A spokeswoman for the U.S. Drug Enforcement Administration said that the agency is studying the opioid but hasn't yet moved to control it.

Nearly eight times more potent than morphine, U-47700 comes in various forms and can be injected, snorted or taken orally.

The U in the name stands for Upjohn, a pharmaceutical manufacturer that developed the drug in the mid-1970s as scientists were looking for a synthetic alternative to morphine, said Barry Logan, chief of forensic toxicology at NMS Labs in Willow Grove, Pennsylvania, which provides lab services for government and private clients.

"They were searching for a novel painkilling drug, the holy grail of analgesics that didn't have the addictive or respiratory depression properties of opiates or heroin," said Logan, who recently spoke about synthetic opioids at an international conference in Budapest.

The Upjohn researchers devised and patented several different compounds in search of their super drug, Logan said. Some of the compounds were written about in scientific literature, including methods for making them.

Chemists in China and Eastern Europe can find recipes for many of the drugs — including U-47700 — by combing through online patent records and old scientific journals, he said.

NMS has identified about 50 deaths across the U.S. that can be connected to U-47700, which came onto the company's radar screen in December, Logan said.